Question

If petrol has a density of 800 kg/m^3 and the discharge nozzle is located 8 mm above the level of petrol in a float chamber. What is the pressure differential causing airflow?

(a) 62.78 Pa

(b) 42.78 Pa

(c) 52.78 Pa

(d) 72.78 Pa

Answer 1

The correct option is (a) 62.78 Pa

To explain: When the fuel flow just starts ΔPf = 0 i.e. ΔPa – ghρf = 0. (ΔPf = pressure differential causing fuel flow, ΔPa = pressure differential causing airflow, h = height of nozzle above the fuel level, ρf = density of fuel) ΔPa – 9.81*(8*10^-3)*800 = 0 i.e. ΔPa = 62.78 Pa.